// target.h -- target support for gold -*- C++ -*-
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
// The abstract class Target is the interface for target specific
// support. It defines abstract methods which each target must
// implement. Typically there will be one target per processor, but
#ifndef GOLD_TARGET_H
#define GOLD_TARGET_H
-#include <cassert>
-
#include "elfcpp.h"
-#include "symtab.h"
+#include "options.h"
+#include "parameters.h"
+#include "stringpool.h"
+#include "debug.h"
namespace gold
{
-class General_options;
class Object;
+class Relobj;
template<int size, bool big_endian>
-class Sized_object;
+class Sized_relobj;
+template<int size, bool big_endian>
+class Sized_relobj_file;
+class Relocatable_relocs;
template<int size, bool big_endian>
struct Relocate_info;
+class Reloc_symbol_changes;
+class Symbol;
+template<int size>
+class Sized_symbol;
+class Symbol_table;
+class Output_data;
+class Output_data_got_base;
+class Output_section;
+class Input_objects;
+class Task;
+struct Symbol_location;
+class Versions;
// The abstract class for target specific handling.
machine_code() const
{ return this->pti_->machine_code; }
+ // Processor specific flags to store in e_flags field of ELF header.
+ elfcpp::Elf_Word
+ processor_specific_flags() const
+ { return this->processor_specific_flags_; }
+
+ // Whether processor specific flags are set at least once.
+ bool
+ are_processor_specific_flags_set() const
+ { return this->are_processor_specific_flags_set_; }
+
// Whether this target has a specific make_symbol function.
bool
has_make_symbol() const
has_resolve() const
{ return this->pti_->has_resolve; }
+ // Whether this target has a specific code fill function.
+ bool
+ has_code_fill() const
+ { return this->pti_->has_code_fill; }
+
+ // Return the default name of the dynamic linker.
+ const char*
+ dynamic_linker() const
+ { return this->pti_->dynamic_linker; }
+
// Return the default address to use for the text segment.
+ // If a -z max-page-size argument has set the ABI page size
+ // to a value larger than the default starting address,
+ // bump the starting address up to the page size, to avoid
+ // misaligning the text segment in the file.
uint64_t
- text_segment_address() const
- { return this->pti_->text_segment_address; }
+ default_text_segment_address() const
+ {
+ uint64_t addr = this->pti_->default_text_segment_address;
+ uint64_t pagesize = this->abi_pagesize();
+ if (addr < pagesize)
+ addr = pagesize;
+ return addr;
+ }
// Return the ABI specified page size.
uint64_t
abi_pagesize() const
- { return this->pti_->abi_pagesize; }
+ {
+ if (parameters->options().max_page_size() > 0)
+ return parameters->options().max_page_size();
+ else
+ return this->pti_->abi_pagesize;
+ }
// Return the common page size used on actual systems.
uint64_t
common_pagesize() const
- { return this->pti_->common_pagesize; }
+ {
+ if (parameters->options().common_page_size() > 0)
+ return std::min(parameters->options().common_page_size(),
+ this->abi_pagesize());
+ else
+ return std::min(this->pti_->common_pagesize,
+ this->abi_pagesize());
+ }
+
+ // Return whether PF_X segments must contain nothing but the contents of
+ // SHF_EXECINSTR sections (no non-executable data, no headers).
+ bool
+ isolate_execinstr() const
+ { return this->pti_->isolate_execinstr; }
+
+ uint64_t
+ rosegment_gap() const
+ { return this->pti_->rosegment_gap; }
+
+ // If we see some object files with .note.GNU-stack sections, and
+ // some objects files without them, this returns whether we should
+ // consider the object files without them to imply that the stack
+ // should be executable.
+ bool
+ is_default_stack_executable() const
+ { return this->pti_->is_default_stack_executable; }
+
+ // Return a character which may appear as a prefix for a wrap
+ // symbol. If this character appears, we strip it when checking for
+ // wrapping and add it back when forming the final symbol name.
+ // This should be '\0' if not special prefix is required, which is
+ // the normal case.
+ char
+ wrap_char() const
+ { return this->pti_->wrap_char; }
+
+ // Return the special section index which indicates a small common
+ // symbol. This will return SHN_UNDEF if there are no small common
+ // symbols.
+ elfcpp::Elf_Half
+ small_common_shndx() const
+ { return this->pti_->small_common_shndx; }
+
+ // Return values to add to the section flags for the section holding
+ // small common symbols.
+ elfcpp::Elf_Xword
+ small_common_section_flags() const
+ {
+ gold_assert(this->pti_->small_common_shndx != elfcpp::SHN_UNDEF);
+ return this->pti_->small_common_section_flags;
+ }
+
+ // Return the special section index which indicates a large common
+ // symbol. This will return SHN_UNDEF if there are no large common
+ // symbols.
+ elfcpp::Elf_Half
+ large_common_shndx() const
+ { return this->pti_->large_common_shndx; }
+
+ // Return values to add to the section flags for the section holding
+ // large common symbols.
+ elfcpp::Elf_Xword
+ large_common_section_flags() const
+ {
+ gold_assert(this->pti_->large_common_shndx != elfcpp::SHN_UNDEF);
+ return this->pti_->large_common_section_flags;
+ }
+
+ // This hook is called when an output section is created.
+ void
+ new_output_section(Output_section* os) const
+ { this->do_new_output_section(os); }
+
+ // This is called to tell the target to complete any sections it is
+ // handling. After this all sections must have their final size.
+ void
+ finalize_sections(Layout* layout, const Input_objects* input_objects,
+ Symbol_table* symtab)
+ { return this->do_finalize_sections(layout, input_objects, symtab); }
+
+ // Return the value to use for a global symbol which needs a special
+ // value in the dynamic symbol table. This will only be called if
+ // the backend first calls symbol->set_needs_dynsym_value().
+ uint64_t
+ dynsym_value(const Symbol* sym) const
+ { return this->do_dynsym_value(sym); }
+
+ // Return a string to use to fill out a code section. This is
+ // basically one or more NOPS which must fill out the specified
+ // length in bytes.
+ std::string
+ code_fill(section_size_type length) const
+ { return this->do_code_fill(length); }
+
+ // Return whether SYM is known to be defined by the ABI. This is
+ // used to avoid inappropriate warnings about undefined symbols.
+ bool
+ is_defined_by_abi(const Symbol* sym) const
+ { return this->do_is_defined_by_abi(sym); }
+
+ // Adjust the output file header before it is written out. VIEW
+ // points to the header in external form. LEN is the length.
+ void
+ adjust_elf_header(unsigned char* view, int len)
+ { return this->do_adjust_elf_header(view, len); }
+
+ // Return address and size to plug into eh_frame FDEs associated with a PLT.
+ void
+ plt_fde_location(const Output_data* plt, unsigned char* oview,
+ uint64_t* address, off_t* len) const
+ { return this->do_plt_fde_location(plt, oview, address, len); }
+
+ // Return whether NAME is a local label name. This is used to implement the
+ // --discard-locals options.
+ bool
+ is_local_label_name(const char* name) const
+ { return this->do_is_local_label_name(name); }
+
+ // Get the symbol index to use for a target specific reloc.
+ unsigned int
+ reloc_symbol_index(void* arg, unsigned int type) const
+ { return this->do_reloc_symbol_index(arg, type); }
+
+ // Get the addend to use for a target specific reloc.
+ uint64_t
+ reloc_addend(void* arg, unsigned int type, uint64_t addend) const
+ { return this->do_reloc_addend(arg, type, addend); }
+
+ // Return the PLT address to use for a global symbol.
+ uint64_t
+ plt_address_for_global(const Symbol* sym) const
+ { return this->do_plt_address_for_global(sym); }
+
+ // Return the PLT address to use for a local symbol.
+ uint64_t
+ plt_address_for_local(const Relobj* object, unsigned int symndx) const
+ { return this->do_plt_address_for_local(object, symndx); }
+
+ // Return the offset to use for the GOT_INDX'th got entry which is
+ // for a local tls symbol specified by OBJECT, SYMNDX.
+ int64_t
+ tls_offset_for_local(const Relobj* object,
+ unsigned int symndx,
+ unsigned int got_indx) const
+ { return do_tls_offset_for_local(object, symndx, got_indx); }
+
+ // Return the offset to use for the GOT_INDX'th got entry which is
+ // for global tls symbol GSYM.
+ int64_t
+ tls_offset_for_global(Symbol* gsym, unsigned int got_indx) const
+ { return do_tls_offset_for_global(gsym, got_indx); }
+
+ // For targets that use function descriptors, if LOC is the location
+ // of a function, modify it to point at the function entry location.
+ void
+ function_location(Symbol_location* loc) const
+ { return do_function_location(loc); }
+
+ // Return whether this target can use relocation types to determine
+ // if a function's address is taken.
+ bool
+ can_check_for_function_pointers() const
+ { return this->do_can_check_for_function_pointers(); }
+
+ // Return whether a relocation to a merged section can be processed
+ // to retrieve the contents.
+ bool
+ can_icf_inline_merge_sections () const
+ { return this->pti_->can_icf_inline_merge_sections; }
+
+ // Whether a section called SECTION_NAME may have function pointers to
+ // sections not eligible for safe ICF folding.
+ virtual bool
+ section_may_have_icf_unsafe_pointers(const char* section_name) const
+ { return this->do_section_may_have_icf_unsafe_pointers(section_name); }
+
+ // Return the base to use for the PC value in an FDE when it is
+ // encoded using DW_EH_PE_datarel. This does not appear to be
+ // documented anywhere, but it is target specific. Any use of
+ // DW_EH_PE_datarel in gcc requires defining a special macro
+ // (ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX) to output the value.
+ uint64_t
+ ehframe_datarel_base() const
+ { return this->do_ehframe_datarel_base(); }
+
+ // Return true if a reference to SYM from a reloc at *PRELOC
+ // means that the current function may call an object compiled
+ // without -fsplit-stack. SYM is known to be defined in an object
+ // compiled without -fsplit-stack.
+ bool
+ is_call_to_non_split(const Symbol* sym, const unsigned char* preloc,
+ const unsigned char* view,
+ section_size_type view_size) const
+ { return this->do_is_call_to_non_split(sym, preloc, view, view_size); }
+
+ // A function starts at OFFSET in section SHNDX in OBJECT. That
+ // function was compiled with -fsplit-stack, but it refers to a
+ // function which was compiled without -fsplit-stack. VIEW is a
+ // modifiable view of the section; VIEW_SIZE is the size of the
+ // view. The target has to adjust the function so that it allocates
+ // enough stack.
+ void
+ calls_non_split(Relobj* object, unsigned int shndx,
+ section_offset_type fnoffset, section_size_type fnsize,
+ const unsigned char* prelocs, size_t reloc_count,
+ unsigned char* view, section_size_type view_size,
+ std::string* from, std::string* to) const
+ {
+ this->do_calls_non_split(object, shndx, fnoffset, fnsize,
+ prelocs, reloc_count, view, view_size,
+ from, to);
+ }
+
+ // Make an ELF object.
+ template<int size, bool big_endian>
+ Object*
+ make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<size, big_endian>& ehdr)
+ { return this->do_make_elf_object(name, input_file, offset, ehdr); }
+
+ // Make an output section.
+ Output_section*
+ make_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags)
+ { return this->do_make_output_section(name, type, flags); }
+
+ // Return true if target wants to perform relaxation.
+ bool
+ may_relax() const
+ {
+ // Run the dummy relaxation pass twice if relaxation debugging is enabled.
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ return true;
+
+ return this->do_may_relax();
+ }
+
+ // Perform a relaxation pass. Return true if layout may be changed.
+ bool
+ relax(int pass, const Input_objects* input_objects, Symbol_table* symtab,
+ Layout* layout, const Task* task)
+ {
+ // Run the dummy relaxation pass twice if relaxation debugging is enabled.
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ return pass < 2;
+
+ return this->do_relax(pass, input_objects, symtab, layout, task);
+ }
+
+ // Return the target-specific name of attributes section. This is
+ // NULL if a target does not use attributes section or if it uses
+ // the default section name ".gnu.attributes".
+ const char*
+ attributes_section() const
+ { return this->pti_->attributes_section; }
+
+ // Return the vendor name of vendor attributes.
+ const char*
+ attributes_vendor() const
+ { return this->pti_->attributes_vendor; }
+
+ // Whether a section called NAME is an attribute section.
+ bool
+ is_attributes_section(const char* name) const
+ {
+ return ((this->pti_->attributes_section != NULL
+ && strcmp(name, this->pti_->attributes_section) == 0)
+ || strcmp(name, ".gnu.attributes") == 0);
+ }
+
+ // Return a bit mask of argument types for attribute with TAG.
+ int
+ attribute_arg_type(int tag) const
+ { return this->do_attribute_arg_type(tag); }
+
+ // Return the attribute tag of the position NUM in the list of fixed
+ // attributes. Normally there is no reordering and
+ // attributes_order(NUM) == NUM.
+ int
+ attributes_order(int num) const
+ { return this->do_attributes_order(num); }
+
+ // When a target is selected as the default target, we call this method,
+ // which may be used for expensive, target-specific initialization.
+ void
+ select_as_default_target()
+ { this->do_select_as_default_target(); }
+
+ // Return the value to store in the EI_OSABI field in the ELF
+ // header.
+ elfcpp::ELFOSABI
+ osabi() const
+ { return this->osabi_; }
+
+ // Set the value to store in the EI_OSABI field in the ELF header.
+ void
+ set_osabi(elfcpp::ELFOSABI osabi)
+ { this->osabi_ = osabi; }
+
+ // Define target-specific standard symbols.
+ void
+ define_standard_symbols(Symbol_table* symtab, Layout* layout)
+ { this->do_define_standard_symbols(symtab, layout); }
+
+ // Return the output section name to use given an input section
+ // name, or NULL if no target specific name mapping is required.
+ // Set *PLEN to the length of the name if returning non-NULL.
+ const char*
+ output_section_name(const Relobj* relobj,
+ const char* name,
+ size_t* plen) const
+ { return this->do_output_section_name(relobj, name, plen); }
+
+ // Add any special sections for this symbol to the gc work list.
+ void
+ gc_mark_symbol(Symbol_table* symtab, Symbol* sym) const
+ { this->do_gc_mark_symbol(symtab, sym); }
+
+ // Return the name of the entry point symbol.
+ const char*
+ entry_symbol_name() const
+ { return this->pti_->entry_symbol_name; }
+
+ // Return the size in bits of SHT_HASH entry.
+ int
+ hash_entry_size() const
+ { return this->pti_->hash_entry_size; }
+
+ // Return the section type to use for unwind sections.
+ unsigned int
+ unwind_section_type() const
+ { return this->pti_->unwind_section_type; }
+
+ // Whether the target has a custom set_dynsym_indexes method.
+ bool
+ has_custom_set_dynsym_indexes() const
+ { return this->do_has_custom_set_dynsym_indexes(); }
+
+ // Custom set_dynsym_indexes method for a target.
+ unsigned int
+ set_dynsym_indexes(std::vector<Symbol*>* dyn_symbols, unsigned int index,
+ std::vector<Symbol*>* syms, Stringpool* dynpool,
+ Versions* versions, Symbol_table* symtab) const
+ {
+ return this->do_set_dynsym_indexes(dyn_symbols, index, syms, dynpool,
+ versions, symtab);
+ }
+
+ // Get the custom dynamic tag value.
+ unsigned int
+ dynamic_tag_custom_value(elfcpp::DT tag) const
+ { return this->do_dynamic_tag_custom_value(tag); }
+
+ // Adjust the value written to the dynamic symbol table.
+ void
+ adjust_dyn_symbol(const Symbol* sym, unsigned char* view) const
+ { this->do_adjust_dyn_symbol(sym, view); }
+
+ // Return whether to include the section in the link.
+ bool
+ should_include_section(elfcpp::Elf_Word sh_type) const
+ { return this->do_should_include_section(sh_type); }
+
+ // Finalize the target-specific properties in the .note.gnu.property section.
+ void
+ finalize_gnu_properties(Layout* layout) const
+ { this->do_finalize_gnu_properties(layout); }
protected:
// This struct holds the constant information for a child class. We
bool has_make_symbol;
// Whether this target has a specific resolve function.
bool has_resolve;
+ // Whether this target has a specific code fill function.
+ bool has_code_fill;
+ // Whether an object file with no .note.GNU-stack sections implies
+ // that the stack should be executable.
+ bool is_default_stack_executable;
+ // Whether a relocation to a merged section can be processed to
+ // retrieve the contents.
+ bool can_icf_inline_merge_sections;
+ // Prefix character to strip when checking for wrapping.
+ char wrap_char;
+ // The default dynamic linker name.
+ const char* dynamic_linker;
// The default text segment address.
- uint64_t text_segment_address;
+ uint64_t default_text_segment_address;
// The ABI specified page size.
uint64_t abi_pagesize;
// The common page size used by actual implementations.
uint64_t common_pagesize;
+ // Whether PF_X segments must contain nothing but the contents of
+ // SHF_EXECINSTR sections (no non-executable data, no headers).
+ bool isolate_execinstr;
+ // If nonzero, distance from the text segment to the read-only segment.
+ uint64_t rosegment_gap;
+ // The special section index for small common symbols; SHN_UNDEF
+ // if none.
+ elfcpp::Elf_Half small_common_shndx;
+ // The special section index for large common symbols; SHN_UNDEF
+ // if none.
+ elfcpp::Elf_Half large_common_shndx;
+ // Section flags for small common section.
+ elfcpp::Elf_Xword small_common_section_flags;
+ // Section flags for large common section.
+ elfcpp::Elf_Xword large_common_section_flags;
+ // Name of attributes section if it is not ".gnu.attributes".
+ const char* attributes_section;
+ // Vendor name of vendor attributes.
+ const char* attributes_vendor;
+ // Name of the main entry point to the program.
+ const char* entry_symbol_name;
+ // Size (in bits) of SHT_HASH entry. Always equal to 32, except for
+ // 64-bit S/390.
+ const int hash_entry_size;
+ // Processor-specific section type for ".eh_frame" (unwind) sections.
+ // SHT_PROGBITS if there is no special section type.
+ const unsigned int unwind_section_type;
};
Target(const Target_info* pti)
- : pti_(pti)
+ : pti_(pti), processor_specific_flags_(0),
+ are_processor_specific_flags_set_(false), osabi_(elfcpp::ELFOSABI_NONE)
+ { }
+
+ // Virtual function which may be implemented by the child class.
+ virtual void
+ do_new_output_section(Output_section*) const
+ { }
+
+ // Virtual function which may be implemented by the child class.
+ virtual void
+ do_finalize_sections(Layout*, const Input_objects*, Symbol_table*)
+ { }
+
+ // Virtual function which may be implemented by the child class.
+ virtual uint64_t
+ do_dynsym_value(const Symbol*) const
+ { gold_unreachable(); }
+
+ // Virtual function which must be implemented by the child class if
+ // needed.
+ virtual std::string
+ do_code_fill(section_size_type) const
+ { gold_unreachable(); }
+
+ // Virtual function which may be implemented by the child class.
+ virtual bool
+ do_is_defined_by_abi(const Symbol*) const
+ { return false; }
+
+ // Adjust the output file header before it is written out. VIEW
+ // points to the header in external form. LEN is the length, and
+ // will be one of the values of elfcpp::Elf_sizes<size>::ehdr_size.
+ // By default, we set the EI_OSABI field if requested (in
+ // Sized_target).
+ virtual void
+ do_adjust_elf_header(unsigned char*, int) = 0;
+
+ // Return address and size to plug into eh_frame FDEs associated with a PLT.
+ virtual void
+ do_plt_fde_location(const Output_data* plt, unsigned char* oview,
+ uint64_t* address, off_t* len) const;
+
+ // Virtual function which may be overridden by the child class.
+ virtual bool
+ do_is_local_label_name(const char*) const;
+
+ // Virtual function that must be overridden by a target which uses
+ // target specific relocations.
+ virtual unsigned int
+ do_reloc_symbol_index(void*, unsigned int) const
+ { gold_unreachable(); }
+
+ // Virtual function that must be overridden by a target which uses
+ // target specific relocations.
+ virtual uint64_t
+ do_reloc_addend(void*, unsigned int, uint64_t) const
+ { gold_unreachable(); }
+
+ // Virtual functions that must be overridden by a target that uses
+ // STT_GNU_IFUNC symbols.
+ virtual uint64_t
+ do_plt_address_for_global(const Symbol*) const
+ { gold_unreachable(); }
+
+ virtual uint64_t
+ do_plt_address_for_local(const Relobj*, unsigned int) const
+ { gold_unreachable(); }
+
+ virtual int64_t
+ do_tls_offset_for_local(const Relobj*, unsigned int, unsigned int) const
+ { gold_unreachable(); }
+
+ virtual int64_t
+ do_tls_offset_for_global(Symbol*, unsigned int) const
+ { gold_unreachable(); }
+
+ virtual void
+ do_function_location(Symbol_location*) const = 0;
+
+ // Virtual function which may be overriden by the child class.
+ virtual bool
+ do_can_check_for_function_pointers() const
+ { return false; }
+
+ // Virtual function which may be overridden by the child class. We
+ // recognize some default sections for which we don't care whether
+ // they have function pointers.
+ virtual bool
+ do_section_may_have_icf_unsafe_pointers(const char* section_name) const
+ {
+ // We recognize sections for normal vtables, construction vtables and
+ // EH frames.
+ return (!is_prefix_of(".rodata._ZTV", section_name)
+ && !is_prefix_of(".data.rel.ro._ZTV", section_name)
+ && !is_prefix_of(".rodata._ZTC", section_name)
+ && !is_prefix_of(".data.rel.ro._ZTC", section_name)
+ && !is_prefix_of(".eh_frame", section_name));
+ }
+
+ virtual uint64_t
+ do_ehframe_datarel_base() const
+ { gold_unreachable(); }
+
+ // Virtual function which may be overridden by the child class. The
+ // default implementation is that any function not defined by the
+ // ABI is a call to a non-split function.
+ virtual bool
+ do_is_call_to_non_split(const Symbol* sym, const unsigned char*,
+ const unsigned char*, section_size_type) const;
+
+ // Virtual function which may be overridden by the child class.
+ virtual void
+ do_calls_non_split(Relobj* object, unsigned int, section_offset_type,
+ section_size_type, const unsigned char*, size_t,
+ unsigned char*, section_size_type,
+ std::string*, std::string*) const;
+
+ // make_elf_object hooks. There are four versions of these for
+ // different address sizes and endianness.
+
+ // Set processor specific flags.
+ void
+ set_processor_specific_flags(elfcpp::Elf_Word flags)
+ {
+ this->processor_specific_flags_ = flags;
+ this->are_processor_specific_flags_set_ = true;
+ }
+
+#ifdef HAVE_TARGET_32_LITTLE
+ // Virtual functions which may be overridden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<32, false>&);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+ // Virtual functions which may be overridden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<32, true>&);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+ // Virtual functions which may be overridden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<64, false>& ehdr);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+ // Virtual functions which may be overridden by the child class.
+ virtual Object*
+ do_make_elf_object(const std::string& name, Input_file* input_file,
+ off_t offset, const elfcpp::Ehdr<64, true>& ehdr);
+#endif
+
+ // Virtual functions which may be overridden by the child class.
+ virtual Output_section*
+ do_make_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags);
+
+ // Virtual function which may be overridden by the child class.
+ virtual bool
+ do_may_relax() const
+ { return parameters->options().relax(); }
+
+ // Virtual function which may be overridden by the child class.
+ virtual bool
+ do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*)
+ { return false; }
+
+ // A function for targets to call. Return whether BYTES/LEN matches
+ // VIEW/VIEW_SIZE at OFFSET.
+ bool
+ match_view(const unsigned char* view, section_size_type view_size,
+ section_offset_type offset, const char* bytes, size_t len) const;
+
+ // Set the contents of a VIEW/VIEW_SIZE to nops starting at OFFSET
+ // for LEN bytes.
+ void
+ set_view_to_nop(unsigned char* view, section_size_type view_size,
+ section_offset_type offset, size_t len) const;
+
+ // This must be overridden by the child class if it has target-specific
+ // attributes subsection in the attribute section.
+ virtual int
+ do_attribute_arg_type(int) const
+ { gold_unreachable(); }
+
+ // This may be overridden by the child class.
+ virtual int
+ do_attributes_order(int num) const
+ { return num; }
+
+ // This may be overridden by the child class.
+ virtual void
+ do_select_as_default_target()
+ { }
+
+ // This may be overridden by the child class.
+ virtual void
+ do_define_standard_symbols(Symbol_table*, Layout*)
+ { }
+
+ // This may be overridden by the child class.
+ virtual const char*
+ do_output_section_name(const Relobj*, const char*, size_t*) const
+ { return NULL; }
+
+ // This may be overridden by the child class.
+ virtual void
+ do_gc_mark_symbol(Symbol_table*, Symbol*) const
+ { }
+
+ // This may be overridden by the child class.
+ virtual bool
+ do_has_custom_set_dynsym_indexes() const
+ { return false; }
+
+ // This may be overridden by the child class.
+ virtual unsigned int
+ do_set_dynsym_indexes(std::vector<Symbol*>*, unsigned int,
+ std::vector<Symbol*>*, Stringpool*, Versions*,
+ Symbol_table*) const
+ { gold_unreachable(); }
+
+ // This may be overridden by the child class.
+ virtual unsigned int
+ do_dynamic_tag_custom_value(elfcpp::DT) const
+ { gold_unreachable(); }
+
+ // This may be overridden by the child class.
+ virtual void
+ do_adjust_dyn_symbol(const Symbol*, unsigned char*) const
+ { }
+
+ // This may be overridden by the child class.
+ virtual bool
+ do_should_include_section(elfcpp::Elf_Word) const
+ { return true; }
+
+ // Finalize the target-specific properties in the .note.gnu.property section.
+ virtual void
+ do_finalize_gnu_properties(Layout*) const
{ }
private:
+ // The implementations of the four do_make_elf_object virtual functions are
+ // almost identical except for their sizes and endianness. We use a template.
+ // for their implementations.
+ template<int size, bool big_endian>
+ inline Object*
+ do_make_elf_object_implementation(const std::string&, Input_file*, off_t,
+ const elfcpp::Ehdr<size, big_endian>&);
+
Target(const Target&);
Target& operator=(const Target&);
// The target information.
const Target_info* pti_;
+ // Processor-specific flags.
+ elfcpp::Elf_Word processor_specific_flags_;
+ // Whether the processor-specific flags are set at least once.
+ bool are_processor_specific_flags_set_;
+ // If not ELFOSABI_NONE, the value to put in the EI_OSABI field of
+ // the ELF header. This is handled at this level because it is
+ // OS-specific rather than processor-specific.
+ elfcpp::ELFOSABI osabi_;
};
// The abstract class for a specific size and endianness of target.
// symbol table. This will only be called if has_make_symbol()
// returns true.
virtual Sized_symbol<size>*
- make_symbol()
- { abort(); }
+ make_symbol(const char*, elfcpp::STT, Object*, unsigned int, uint64_t)
+ { gold_unreachable(); }
// Resolve a symbol for the target. This should be overridden by a
// target which needs to take special action. TO is the
// pre-existing symbol. SYM is the new symbol, seen in OBJECT.
- // This will only be called if has_resolve() returns true.
+ // VERSION is the version of SYM. This will only be called if
+ // has_resolve() returns true.
+ virtual bool
+ resolve(Symbol*, const elfcpp::Sym<size, big_endian>&, Object*,
+ const char*)
+ { gold_unreachable(); }
+
+ // Process the relocs for a section, and record information of the
+ // mapping from source to destination sections. This mapping is later
+ // used to determine unreferenced garbage sections. This procedure is
+ // only called during garbage collection.
virtual void
- resolve(Symbol*, const elfcpp::Sym<size, big_endian>&, Object*)
- { abort(); }
+ gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols) = 0;
// Scan the relocs for a section, and record any information
- // required for the symbol. OPTIONS is the command line options.
- // SYMTAB is the symbol table. OBJECT is the object in which the
- // section appears. SH_TYPE is the type of the relocation section,
- // SHT_REL or SHT_RELA. PRELOCS points to the relocation data.
- // RELOC_COUNT is the number of relocs. LOCAL_SYMBOL_COUNT is the
- // number of local symbols. PLOCAL_SYMBOLS points to the local
- // symbol data from OBJECT. GLOBAL_SYMBOLS is the array of pointers
- // to the global symbol table from OBJECT.
- virtual void
- scan_relocs(const General_options& options,
- Symbol_table* symtab,
- Sized_object<size, big_endian>* object,
+ // required for the symbol. SYMTAB is the symbol table. OBJECT is
+ // the object in which the section appears. DATA_SHNDX is the
+ // section index that these relocs apply to. SH_TYPE is the type of
+ // the relocation section, SHT_REL or SHT_RELA. PRELOCS points to
+ // the relocation data. RELOC_COUNT is the number of relocs.
+ // LOCAL_SYMBOL_COUNT is the number of local symbols.
+ // OUTPUT_SECTION is the output section.
+ // NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets to the output
+ // sections are not mapped as usual. PLOCAL_SYMBOLS points to the
+ // local symbol data from OBJECT. GLOBAL_SYMBOLS is the array of
+ // pointers to the global symbol table from OBJECT.
+ virtual void
+ scan_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, big_endian>* object,
+ unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
size_t local_symbol_count,
- const unsigned char* plocal_symbols,
- Symbol** global_symbols) = 0;
+ const unsigned char* plocal_symbols) = 0;
// Relocate section data. SH_TYPE is the type of the relocation
// section, SHT_REL or SHT_RELA. PRELOCS points to the relocation
- // information. RELOC_COUNT is the number of relocs. VIEW is a
- // view into the output file holding the section contents,
- // VIEW_ADDRESS is the virtual address of the view, and VIEW_SIZE is
- // the size of the view.
+ // information. RELOC_COUNT is the number of relocs.
+ // OUTPUT_SECTION is the output section.
+ // NEEDS_SPECIAL_OFFSET_HANDLING is true if offsets must be mapped
+ // to correspond to the output section. VIEW is a view into the
+ // output file holding the section contents, VIEW_ADDRESS is the
+ // virtual address of the view, and VIEW_SIZE is the size of the
+ // view. If NEEDS_SPECIAL_OFFSET_HANDLING is true, the VIEW_xx
+ // parameters refer to the complete output section data, not just
+ // the input section data.
virtual void
relocate_section(const Relocate_info<size, big_endian>*,
unsigned int sh_type,
const unsigned char* prelocs,
size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
- off_t view_size) = 0;
+ section_size_type view_size,
+ const Reloc_symbol_changes*) = 0;
+
+ // Scan the relocs during a relocatable link. The parameters are
+ // like scan_relocs, with an additional Relocatable_relocs
+ // parameter, used to record the disposition of the relocs.
+ virtual void
+ scan_relocatable_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs*) = 0;
+
+ // Scan the relocs for --emit-relocs. The parameters are
+ // like scan_relocatable_relocs.
+ virtual void
+ emit_relocs_scan(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, big_endian>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_syms,
+ Relocatable_relocs* rr) = 0;
+
+ // Emit relocations for a section during a relocatable link, and for
+ // --emit-relocs. The parameters are like relocate_section, with
+ // additional parameters for the view of the output reloc section.
+ virtual void
+ relocate_relocs(const Relocate_info<size, big_endian>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ typename elfcpp::Elf_types<size>::Elf_Off
+ offset_in_output_section,
+ unsigned char* view,
+ typename elfcpp::Elf_types<size>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size) = 0;
+
+ // Perform target-specific processing in a relocatable link. This is
+ // only used if we use the relocation strategy RELOC_SPECIAL.
+ // RELINFO points to a Relocation_info structure. SH_TYPE is the relocation
+ // section type. PRELOC_IN points to the original relocation. RELNUM is
+ // the index number of the relocation in the relocation section.
+ // OUTPUT_SECTION is the output section to which the relocation is applied.
+ // OFFSET_IN_OUTPUT_SECTION is the offset of the relocation input section
+ // within the output section. VIEW points to the output view of the
+ // output section. VIEW_ADDRESS is output address of the view. VIEW_SIZE
+ // is the size of the output view and PRELOC_OUT points to the new
+ // relocation in the output object.
+ //
+ // A target only needs to override this if the generic code in
+ // target-reloc.h cannot handle some relocation types.
+
+ virtual void
+ relocate_special_relocatable(const Relocate_info<size, big_endian>*
+ /*relinfo */,
+ unsigned int /* sh_type */,
+ const unsigned char* /* preloc_in */,
+ size_t /* relnum */,
+ Output_section* /* output_section */,
+ typename elfcpp::Elf_types<size>::Elf_Off
+ /* offset_in_output_section */,
+ unsigned char* /* view */,
+ typename elfcpp::Elf_types<size>::Elf_Addr
+ /* view_address */,
+ section_size_type /* view_size */,
+ unsigned char* /* preloc_out*/)
+ { gold_unreachable(); }
+
+ // Return the number of entries in the GOT. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this to support incremental linking.
+
+ virtual unsigned int
+ got_entry_count() const
+ { gold_unreachable(); }
+
+ // Return the number of entries in the PLT. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this to support incremental linking.
+
+ virtual unsigned int
+ plt_entry_count() const
+ { gold_unreachable(); }
+
+ // Return the offset of the first non-reserved PLT entry. This is
+ // only used for laying out the incremental link info sections.
+ // A target needs to implement this to support incremental linking.
+
+ virtual unsigned int
+ first_plt_entry_offset() const
+ { gold_unreachable(); }
+
+ // Return the size of each PLT entry. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this to support incremental linking.
+
+ virtual unsigned int
+ plt_entry_size() const
+ { gold_unreachable(); }
+
+ // Return the size of each GOT entry. This is only used for
+ // laying out the incremental link info sections. A target needs
+ // to implement this if its GOT size is different.
+
+ virtual unsigned int
+ got_entry_size() const
+ { return size / 8; }
+
+ // Create the GOT and PLT sections for an incremental update.
+ // A target needs to implement this to support incremental linking.
+
+ virtual Output_data_got_base*
+ init_got_plt_for_update(Symbol_table*,
+ Layout*,
+ unsigned int /* got_count */,
+ unsigned int /* plt_count */)
+ { gold_unreachable(); }
+
+ // Reserve a GOT entry for a local symbol, and regenerate any
+ // necessary dynamic relocations.
+ virtual void
+ reserve_local_got_entry(unsigned int /* got_index */,
+ Sized_relobj<size, big_endian>* /* obj */,
+ unsigned int /* r_sym */,
+ unsigned int /* got_type */)
+ { gold_unreachable(); }
+
+ // Reserve a GOT entry for a global symbol, and regenerate any
+ // necessary dynamic relocations.
+ virtual void
+ reserve_global_got_entry(unsigned int /* got_index */, Symbol* /* gsym */,
+ unsigned int /* got_type */)
+ { gold_unreachable(); }
+
+ // Register an existing PLT entry for a global symbol.
+ // A target needs to implement this to support incremental linking.
+
+ virtual void
+ register_global_plt_entry(Symbol_table*, Layout*,
+ unsigned int /* plt_index */,
+ Symbol*)
+ { gold_unreachable(); }
+
+ // Force a COPY relocation for a given symbol.
+ // A target needs to implement this to support incremental linking.
+
+ virtual void
+ emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t)
+ { gold_unreachable(); }
+
+ // Apply an incremental relocation.
+
+ virtual void
+ apply_relocation(const Relocate_info<size, big_endian>* /* relinfo */,
+ typename elfcpp::Elf_types<size>::Elf_Addr /* r_offset */,
+ unsigned int /* r_type */,
+ typename elfcpp::Elf_types<size>::Elf_Swxword /* r_addend */,
+ const Symbol* /* gsym */,
+ unsigned char* /* view */,
+ typename elfcpp::Elf_types<size>::Elf_Addr /* address */,
+ section_size_type /* view_size */)
+ { gold_unreachable(); }
+
+ // Handle target specific gc actions when adding a gc reference from
+ // SRC_OBJ, SRC_SHNDX to a location specified by DST_OBJ, DST_SHNDX
+ // and DST_OFF.
+ void
+ gc_add_reference(Symbol_table* symtab,
+ Relobj* src_obj,
+ unsigned int src_shndx,
+ Relobj* dst_obj,
+ unsigned int dst_shndx,
+ typename elfcpp::Elf_types<size>::Elf_Addr dst_off) const
+ {
+ this->do_gc_add_reference(symtab, src_obj, src_shndx,
+ dst_obj, dst_shndx, dst_off);
+ }
+
+ // Return the r_sym field from a relocation.
+ // Most targets can use the default version of this routine,
+ // but some targets have a non-standard r_info field, and will
+ // need to provide a target-specific version.
+ virtual unsigned int
+ get_r_sym(const unsigned char* preloc) const
+ {
+ // Since REL and RELA relocs share the same structure through
+ // the r_info field, we can just use REL here.
+ elfcpp::Rel<size, big_endian> rel(preloc);
+ return elfcpp::elf_r_sym<size>(rel.get_r_info());
+ }
+
+ // Record a target-specific program property in the .note.gnu.property
+ // section.
+ virtual void
+ record_gnu_property(unsigned int, unsigned int, size_t,
+ const unsigned char*, const Object*)
+ { }
+
+ // Merge the target-specific program properties from the current object.
+ virtual void
+ merge_gnu_properties(const Object*)
+ { }
protected:
Sized_target(const Target::Target_info* pti)
: Target(pti)
{
- assert(pti->size == size);
- assert(pti->is_big_endian ? big_endian : !big_endian);
+ gold_assert(pti->size == size);
+ gold_assert(pti->is_big_endian ? big_endian : !big_endian);
}
+
+ // Set the EI_OSABI field if requested.
+ virtual void
+ do_adjust_elf_header(unsigned char*, int);
+
+ // Handle target specific gc actions when adding a gc reference.
+ virtual void
+ do_gc_add_reference(Symbol_table*, Relobj*, unsigned int,
+ Relobj*, unsigned int,
+ typename elfcpp::Elf_types<size>::Elf_Addr) const
+ { }
+
+ virtual void
+ do_function_location(Symbol_location*) const
+ { }
};
} // End namespace gold.
projects / deliverable / binutils-gdb.git / blobdiff